In commercially available cold light mirror lamps the light passage opening of the mirror reflector is closed by a cover glass which is rigidly and nondetachably connected to the mirror reflector. The cover glass forms a protective means for the lamp and the inside of the mirror reflector, on the one hand, and, on the other hand, an accident prevention means is provided by preventing the lamp, which is particularly hot when turned on, from being touched. Due to the nondetachable connection between the mirror reflector and the cover glass, the entire assembly unit consisting of the mirror reflector, lamp, and cover glass must be replaced in the case of damage to the mirror reflector or cover glass.
In another, commercially available cold light mirror lamp, which is also provided with a cover glass, the cover glass is detachably arranged on the beaded edge of the mirror reflector by means of a holding ring made of sheet metal. This is done either by bending a plurality of flaps formed by cuts in the holding ring over the beaded edge, or by connecting the holding ring to a lamp holder by means of two spring clips passed through corresponding holes in the holding ring. The advantage of the detachable connection between the mirror reflector and the cover glass is opposed by the disadvantage of the increased technical expense, especially in the case of the second version with the spring clips.